|  | 1.6 | The Transport Layer of the OSI Reference Model
| 1.6.2 | Layer 4 segmentation
One reason for using a layered network model is so that several applications can share the same transport connection. Transport functionality is accomplished segment by segment. This means that different applications can send data segments on a first-come, first-served basis. Such segments can be intended for the same destination or for many different destinations.